Re pro amps, there are numerous forums online about swapping out noisy fans on Crown, QSC, Behringer ect....truth is, if you're looking at pro amp power, you'd likely be listening to it so loud you would only notice the fan on the very quietest passages. The other option is simply to have your amps in an isolated area or different room. Behringer's A500 is a fanless option as well.

I have seen a setup with pro amps where most of the equipment is in a server-style rack (with doors etc) which was located under the staircase in a basement. With good isolation, there was no perceptible noise; but I thought the money and effort for the setup could've been used differently.I found out that the love for pro amps is very strong :-).